Over a year late to market, HP needs to give potential tablet shoppers all the reason to buy a TouchPad it can muster. Along with the storage promotion, HP offers a $50 rebate to owners of Palm smartphones — like the Pixi and Pre — through the end of July.

Despite recent security issues, Dropbox attracted a considerable number of users since its launch in 2008, hitting the 25 million user mark in April. Google obviously has its entire suite of cloud-based apps, including the invite-only Music Beta. And of course, Apple’s iCloud is due to drop this fall, offering 5 free gigs of online storage, as well as backups to iOS devices.

Box.net’s offering is actually a fairly nice deal for those needing online storage. The 50 GB of free storage amounts to approximately $240 in yearly savings, as the 50-GB storage costs the average user a $20 monthly subscription fee. Though it’s difficult to compete with Amazon’s storage pricing, which costs only $1 a gig yearly (the first 5 GB are free).

But still, will these packaged freebies make it worth buying the TouchPad? Amazon’s storage locker is available on any Android device, and Google’s suite is available across most platforms (except webOS 3.0, that is). We’re not sure, but if you’re already planning to buy a TouchPad, hit HP’s App Catalog to pick up Box.net’s deal.

The TouchPad launches in the United States this Friday for $500 and $600 for the 16- and 32-GB versions, respectively. The tablet rolls out globally over the rest of July.